In the 1950's John Watson, a radio journalist, and his wife Phyllis witness five mysterious objects falling from the sky and disappearing into the sea. There are many more such sightings, but nobody can explain them. The Navy decide to investigate by dropping a camera into one of the deep places. The ship is destroyed by some sort of electrical force unknown to man.
Then shipping in the deep areas starts being destroyed. The government believes there is a threat that needs to be destroyed, so they 'drop' nuclear weapons. They have some success, but whatever is down there lears to protect themselves. The two main characters follow developments in the situation, and hear of a scientist named Alastair Bocker, who believes Earth has been invaded from space; initially he is ridiculed, but people are swayed to his view when the creatures start attacking humans on remote islands.
A sort of stalemate is achieved, but then Bocker announces that sea level is rising - it seems the creatures are melting the arctic ice from underneath. As the level rises most countries are unable to function and general anarchy sets in. All through this John and Phyllis have been trying to help by broadcasting information, but eventually they agree that they must leave the now flooded London.
They head for a house on the Cornish coast and live there while the sea continues to rise and society continues to collapse, and there they hope that somehow, something can be done to rid the Earth of these creatures...
This report prepared by Alan Tompkins